自然发酵对大米理化性质的影响及其米粉凝胶机理研究

通过对整粒大米 (籼米 )自然发酵过程中理化性质变化的研究 ,探讨传统自然发酵米粉的凝胶机理。研究发现发酵过程中总淀粉及直链淀粉含量并无显著变化 ,蛋白、脂肪和灰分含量随着发酵的进行而明显减少 ,而游离脂肪酸的含量呈上升趋势。流变学测定发现 ,发酵法生产的米粉相对于对照样品最大破断应力减小而最大应变增加。感官评定结果表明发酵法生产的米粉柔韧筋道 ,品质更好。笔者认为自然发酵虽然未影响总淀粉和直链淀粉含量 ,但降解了蛋白和脂肪而改变了大米粉的流变性质。另外灰分的降低赋予米粉洁白的外观 ,带给产品更好的透明感

Influence of Natural Fermentation on the Physicochemical Characteristics of Rice and Gelation Mechanism of Rice Noodle

The objective in this article was to investigate the physicochemical properties during the natural fermentation process of the rice granule, and try to make clear the mechanism of the traditional fermentation process for improving the rheological properties of rice noodles The results revealed both of starch and amylose content changed insignificantly Protein, lipid and ash content in the rice granule decreased gradually but free fatty acid content increased at the beginning of the fermentation and then remained constant Measured by an Instron rheometer, the fermented rice noodle has a lower stress maximum and higher strain maximum It also obtained a chewy mouth feel by organoleptic evaluation It was concluded that the fermentation seems exert its influences on the rice starch properties through removal of protein, lipid and minerals, and emancipated more unlimited starch granules previously bound to inclusion complexes with protein and/or lipids, and it is the unlimited starch that improved the rice noodle rheological properties